Headlamp Levelling Actuator
A small motor in each headlamp that tilts the beam to compensate for the vehicle's attitude. Self-levelling is a legal requirement on gas discharge and most LED headlamps rather than a convenience: four passengers and a loaded boot pitch the nose up by a few degrees, and at those light outputs a few degrees is the difference between illuminating the road and dazzling oncoming drivers.
Failures split by direction, and only one is visible to the driver. The safe response to bad data is to aim the beam down, producing "my headlights suddenly do not reach anywhere" — a pool of light a few metres ahead, genuinely dangerous at speed on an unlit road, and rarely connected to a stored code. A beam left high is the other direction, and the driver never sees it — being flashed repeatedly on dipped beam is the symptom.
The actuator itself fails less often than the ride height sensor feeding it. Two further cases get blamed on it wrongly: a lowered or re-sprung vehicle needs the levelling recalibrated to its new ride height, and an LED or HID bulb in a housing built for halogen produces glare no levelling system can correct, because the beam pattern is wrong rather than the aim.
Also known as: headlight levelling motor, headlamp levelling motor, beam adjuster, headlight adjuster, headlamp aim actuator, auto levelling motor
Referenced by 6 codes
Codes involving this component (6)
- U0181 Lost Communication With Headlamp Leveling Control Module A Moderate
- U0182 Lost Communication With Lighting Control Module — Front Moderate
- U0482 Invalid Data Received From Headlamp Leveling Control Module A Moderate
- U0483 Invalid Data Received From Lighting Control Module — Front Moderate
- U0542 Invalid Data Received From Headlamp Control Module A Moderate
- U0543 Invalid Data Received From Headlamp Control Module B Moderate
Other components in Electrical and Charging
- Data Bus 563
- Battery 218
- Gateway Module 158
- Stability Control Module 122
- Battery Temperature Sensor 115
- Infotainment Head Unit 49
- Alternator 45
- Brake Booster Pressure Sensor 39
- A/C Refrigerant Pressure Sensor 33
- Brake Light Switch 32
- Cruise Control Switch 31
- Ignition Switch 31
- Cooling Fan Relay 28
- Starter Relay 25
- A/C Compressor 25
- Clutch Switch 24
- ECM Power Relay 21
- Roof Antenna Module 19
- Immobiliser 15
- Lighting Driver Control Module 15
- Starter Motor 14
- Transmission Control Module Power Relay 14
- Fuel Pump Relay 13
- Secondary Air Injection Relay 13
- Battery Monitoring Sensor 10
- Driver Information Centre 10
- A/C Evaporator Temperature Sensor 8
- Telematics Control Module 8
- Navigation Control Module 6
- Hydraulic Pump Relay 5
- Head-Up Display 2
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